EDITED BY MRS FRANCES HODGSON BURNETT. [COPYRIGHT.] A Hundred Million of Suns. By Sir Rodert S. Ball, F.R.S

Te Aroha News, Volume VII, Issue 422, 23 November 1889, Page 3

EDITED BY MRS FRANCES HODGSON BURNETT. [COPYRIGHT.] A Hundred Million of Suns. By Sir Rodert S. Ball, F.R.S

Oh all the discoveries which have ever been made in science there are two which especially baflle our powers of comprehension. They lie ab the opposite extremes of nature. One relates to objects which are infinitely small ; the other relates to objects, which are almost infinitely great. The microscope teaches us that there are animals so minute that if a thousand of them were ranked abreast they could easily swim without being thrown out of line through the eye of the finest cambric needle. Each of those minute creatures is a highly organised number of particles, capable of moving about, of finding and devouring its food and of behaving in all. other respects as becomes an animal as distinguished Iroui an unorganised piece of matter. * The mind is incapable of realising the structure of these little creatures and of fully appreciating their marvellous adaptation to the life they are destined to lead. If these animals excite our astonishment by reason of their extreme minuteness, there is an appeal made to conceptions of an entirely different character when we learn the lessons which > the telescope teaches. As the microscope reveals the , excessively minute, so does the telescope disclose the sublimely great. In each case myriads of objects are submitted to our astonished view, but while the microscope brings before us creatures of which countless millions could swim about freely in a thimbleful of water, the telescope conducts our vision to uncounted legions of stars, each of them. millions ot times larger than the entire earth, "" j The grandest truth in the whole of nature "' is/conveyed in that first lesson in astronomy - -^hi<Jb answers the question, What are the stars..?- This is a question that a child will < pesk, «nd I have heard of a child's pretty idea that the stare were little holes in the Vskyto let the glory of heaven shine through. "The philosopher will replace this explanation by another, hardly less poetical, which will enable us to form some more adequate 'notion of the real magnificence of the universe. Each star that we see is, it is true, only a glittering little point of light, but that is merely because we are a long way from it. An electric light which will dazzle your eye when quite close will be reduced to an agreeable illumination if it is at a little distance, will become a faint light a mile away, and at no very great distance will become altogether invisible. We must remember thatT out in space there is plenty of room, there are no bound.-?. Space is an ocean where bottom has never been touched, nor is such a thing conceivable, and therefore when we see light glistening in the far distant depths we cannot ab once conclude that the light is a faint one because it appears to us to be faint. It may be that the light is only faint because it comes from such a tremendous distance. In fact, the brightest light conceivable could bo reduced to the insignificance of a small star, if only it were removed sufficiently far. The most intense light we know comes of course from the light which rules by day, from our sun himself, The sun pours his unrivalled beams around us in all directions ' with prodigal abundance notwithstanding his enormous distance of 93,000,000 of miles/ Leb me describe an experiment with respect to our sun, an experiment, -it is needless to say, which could never be performed, bub the results to which it leads us are none the less certain. Astronomers have demonstrated them in many other ways. Suppose that the sun were gradually to be moved away further and further into Bpace, suppose that by this time to-morrow the great luminary should be twice as far and the day atter that three times, and so on until in a year's'time we would find that the sun \va_s 365 times the distance from us that it is ab present. Let us now trace the changes which we should see in the brilliancy of our orb of day. When he had reached double his distance from us we should find that the light- had decreased to a quarter of its present amount and the heat which we derived from his beams would have decreased in the same proportion. In ten days we should find that the light had become so feeble as to be only one hundredth part of that which we enjoy now. The apparent size of the sun would also be steadily decreasing, for as the distance of a body increases its apparent dimensions diminish. Sometimes the diminution of apparent size with distance is well illustrated on a clock tower. You would hardly believe that the hands and face of a clock like that ab Westminster were so large until you happen to see a man cleaning or repairing it, when he appears a little pigmy irt comparison with the mighty dial which points out the hours, In a similar way, with every increase of distance the apparent size of the sun would decline, and in the lapse of a year the sunlight would only be the feeblest of twilight. The sun itself would remain visible for many years, even if it were steadily moving away, though its lustre would continually decline and ibs size would continually diminish, until at last ib would have shrunk to the insignificance of a small point of light, still visible a8 a glittering object, but too minute to enable any definite form to be perceived. Furthur still the sun might recede until ib passed beyond the reach of vision of the unaided eye. The telescope would, however, be able to pursue the retreating luminary until at last ibsank into fcho depbhs of space beyond bhe reach of any instrument whatever. This little argument will prepare us for an explanation of the stars. They merely appear to us to be points of light of varying degrees of brightness, but we have seen that our own sun might be reduced in lustre to that df the very lowest of the stars if only it was femovedsufficientlyfar. If therefore the stars are -at a great enough distance from our system, it may indeed be that they also are suns possibly equalling or possibly even surpassing our own sun in magnificence. Here is indeed an imposing suggestion. Can it be that bhe host of stars which adorn our midnight sky are actually suns themselves of an importance comparable with our own ? This is a great thought and we

desire to teat it by every means in our power. You will see from the reasoning I have given that; the whole question turns simply on one point, and that is : How far oiFare the stars ? The tiniest point of light that is just seen as a glimmer in the mightiest of telescopes may be indeed a sun as great, or indeed a million times greater than our sun if only that star be sufficiently far off. To find the distanco of a star is a prob'le'ni which taxes the utmost powers of the painstaking astronomer; every refinement of skill in making his measurements and of care in the calculation of his observations has to be lavished on the operation. Alas ! it but too often happens that the astronomer's labours prove to be futile. ' The surveying navigator offcen has to mark on his chart that no boctom could be found in the depths of the sea. His appliances would not work, or work reliably in those ocean abysses ; so, too, the astronomer when he tries to sound the depths of space to the distance of the stars has also to mark, generally speaking 'no bottom here ' as the result of his investigations. When this is the case we know for certain that the star on which his calculations have beon made muat be a gorgeous sun, because we are assured of the enormous greatness of its distance, even though we have not been able to find out what the distance was. There are, however, some few places through the sky where the astronomer's eounding line can, so to speak, touch bottom ; there are a few stars of which we do know the distance, and the result is not a little significant. Nafcuie has, for some wise reason, isolated our sun from all the neighbouring 1 suns which surround us, the very ! nearest of which is at a distance 200,000 j times as great as j>b,afc by which the earth is separated from the sun: Were our sun to be withdrawn from us to a distance so great as that of the very nearest of the stars, our magnificent ruler and benefactor would certainly have lost all his splendour ; he would, in fact, have shrunk to the similitude of a little star not nearly so bright as many of those which we s6e over our heads every night. Imagine the sun's light subdivided into 200,000 parts, each of which would give us only a feeble illumination, and then imagine that each of these parts was again divided into 200,000 parts more, and it is one of these last fragments that would represent the miserable lustre which the sun would then display. Now you will be able to fully the magnificent , truth which astronomy discloses, 1 ,tp up. rldor Ido not think, .^hafc in the whole range.of "nature there is.anyhthought so magnificent or so imposing as', that which teaches us to regard every stas of every constellation as a sun. We cannot indeed* assert that they are all so N great as our sun, but we can affirm with lcoj*->, tainty that many of them are fyr, greater and far more splendid. Considering' that our bun presides over a system of worlds of which the earth is one, and that it gives light and heat to those worlds and guides them in their movements, it would surely greatly enlarge our conceptions of the universe if we were assured that there was even one more sun as large and as splendidly attended as is our own. But now we find that not only is there one additional sun, but that they teem in uncounted thousands through space. Look, for exampie, on the next fine night at the Great Bear, the best known of all our northern constellations, and there you see seven .stars forming the well-known feature. Figure in your mind's eye each one of those stars in the likeness of a majestic sun as bier, warm and as bright as our sun, and look at other parts of the sky and' repeat the process with the other constellations, and your conception of the magnificence of the starry system will begin to assume proper propoition u . But this is only the first step ; you must nexb look at the smaller stars and reflect that they, too, are also suns, only much -further ort, as a general rule, than the brighter stars, though this is by no means in variably the case. Thus your estimate 'of the ji umber of suns in the universe^ will -rise' to thousands, but you will- not stop there, you will get a telescope to ' help you, and to your extreme delight and wonder you will find that there are hosts of star?, too faint to be visible to the eye, but which the telescope will immediately disclo&e. Yo,u will getamore powerful instrument and then* you will perceive that the stars are to be numbered by tens of thousauds and even by millions, and with every fiesh accession of fire in your telescope fresh troops and myriads of suns are* revealed. Suns in clusters, suns strewn thickly here and sparsely there, co ac to give us the notion that the only limit to the number we can see is the power of the telescopes we are using. Attempts at actual numeration are futile, for who can tell the number of the stars ? Wecan, however, form an estimate and by taking samples, so to speak, of the sky here and other samples there, we have been enabled to learn the overwhelming fact that our universe contains at tho very least one hundred millions of suns.